A. Technical Field
The present invention relates to an aqueous paint composition and uses thereof, wherein the aqueous paint composition can be used for surface treatment of such as various plastic materials.
B. Background Art
Various plastic materials such as polypropylene, polyethylene, acrylonitrile-butadiene-styrene (ABS), polyurethane, polyphenylene oxide, polycarbonate and poly(vinyl chloride) are used in various utilities such as automobile interior parts and audio-visual equipment parts.
When desired properties such as chemical resistance, beef tallow staining resistance, alkali resistance and adhesion are imparted to the surfaces of these plastic materials, coating is generally performed using a paint composition which contains a binder resin, a pigment, an additive and the like as necessary and can exert the above properties.
As such a paint composition, in recent years, an aqueous paint composition containing an aqueous solvent such as water as a solvent is becoming used because regulations on the use of organic solvents are becoming strict worldwide from the viewpoint of such as prevention of natural environmental pollution, deterioration of work environment and prevention of fire occurrence.
Hitherto, as aqueous paint compositions, there have been proposed aqueous paint compositions in which such as pigments and additives, capable of exerting desired properties, are contained, as necessary, in resin emulsions (e.g.: carboxyl-group-containing resin emulsions such as acrylic resins, alkyd resins and polyesters; and chlorinated polyolefin resin emulsions such as maleic-acid-modified chlorinated polypropylene resin emulsions) (e.g. WO/93/03104, EP0774500A1, U.S. Pat. No. 6,624,234B1, U.S. Pat. No. 6,599,980B2, etc.).
Since the aforementioned prior aqueous paint compositions are poor in low-temperature curability and get cured at high temperatures, there is a possibility that substrates may be damaged. In addition, the resulting coated films are not only insufficient in water resistance, marring resistance and beef tallow staining resistance, but also have no suitable texturability (hereinafter, simply referred to as “texturability” in some cases), and don't combine them with good balance.